Multistage hf alkylation of isoparaffins by means of olefins



NOV- 4, 1 947- J. B. KIRKPATRICK ET`A1. 2,430,228-

MULTISTAGE HF ALKYLATION OF ISOPARAFFINS BY MEANS OF OLEFINS Filed Jan.25. 1944 Bl/TENE FEED MIXER ISOBl/ANE Bl/TE/VE (addon /zJ' lesrmm,

` A ToRNEY.

Patented Nov. 4, 1947 yMULTISTAGE HF ALKYLATION OF ISO- PARAFFINS BYMEANS F OLEFINS James B. Kirkpatrick, Woodbury, Carleton H. Schlesman,Camden, and Arlle A, OKelly, Woodbury, N. J., assignors to Socony-VacuumOil Company, Incorporated, a corporation of New York Application January25, 1944, Serial No. 519,616

1 claim. 1

This invention relates to synthesis of valuable hydrocarbons bycondensation of hydrocarbon reactants in the presence of a liquid acidcatalyst to obtain hydrocarbon products of higher molecular Weight thanthe charge hydrocarlcions` Important among such reactions are aikylatiomof parafiins, particularly isoparaih'ns, with oleiins and polymerizationof olens. Typical catalysts are hydrogen fluoride, sulfuric acid andphosphoric acid. The effect of various liquid acid catalysts in suchreactions has received considerable attention and the effects oftemperature control have also been studied. It is the general belief inthe art that reactions of this type require'rather close temperaturecontrol in orderV ing the desired intimate contact by violent agitationof a two-phase liquid system. Very expensive contactors having highpower requirements for agitation of the liquid mass are conventionalequipment. The present invention provides means for obtaining propercontact between reactants and catalyst without agitation of the reactionmass.l The invention is also adapted to take advantage of the verymarked advantages in `nature and course of the reaction obtained bypreheating the reactants charged to the system. This is the conceptdescribed in the prior copending application Serial No. 490,487, filedJune 11, 1943, by Arlie A. OKelly and Jacob R. Meadow.

The present invention provides apparatus of relatively simple andinexpensive nature for conducting reactions of the type defined above.According to the present invention, a plurality of reaction zones areprovided; each adapted for passage of hydrocarbons upwardly insubdivided form through a body of liquid acid catalyst. Each of thezones is connected to two other similar zones in order that catalyst mayiiow from zone (Cl. Zim-683.4)

Reference is made to the attached drawing, comprising a single figureillustrating diagrammatically a preferred embodiment of the invention.The plant. shown includes three units, each comprising a reaction vessell having a body 'of liquid catalyst in the lower part anda body ofhydrocarbon thereabove, the interface between the two liquid phasesbeing indicated at 2. Within each vessel l is a device 3 for admittinghydrocarbons, near the bottom of the vessel, into the body of catalyst.In the form shown,l this device is somewhat in the nature of a bubblecap formed of heat insulating material to permit charging hydrocarbonsat a substantial preheat without upsetting heat control of the body ofcatalyst. Disposed within the body' of catalyst is a heat exchange coilt to'maintain the reaction zone at the desired temperature by removingheat of reaction and heat put into the system by charge preheat, if any.

The charge is admitted to the inside of the bubble cap by a'pipe 5 whichhas a jacket 6 about it for use' in preheating the charge. Steam orother heat exchange medium passed through the jacket 6 serves to preheator otherwise affect the temperature of the charge as it flows throughthe pipe 5 and bubble cap 3.

The several reaction vessels l are preferably disposed in verticallyspaced relation to each other in order that flow of the catalyst may beinduced by gravity, although pumps may be used for this purpose. Freshcatalyst is introduced to the system at the uppermost vessel l by meansof a pipe 1 and catalyst iiows from each vessel to a vessel lower in theseries by pipes 8 which have intakes placed at the points desired forhydrocarbon-acid interfaces. Fresh catalyst may be added or may to zonethrough the system in one direction while hydrocarbons flow from zone tozone through the system in the opposite direction. This results incountercurrent contact between catalyst and hydrocarbons through thesystem while permitting separate control of conditions of reaction andconcentration of reactants in each stage.

replace part or all of the catalyst iiowing downwardly through theseries by insertion of suitable connections for that purpose in thepipes 8. Catalysl-l is withdrawn by pipe 9 and may thereafter be treatedin conventional manner to regenerate it for reuse in the process.

. Some sort of indicator of interface level in the lowest reactor isdesirable and there is illustrated heren a float actuated electricindicator shown at l The flow of hydrocarbons through the system is inthe direction opposite to that of catalyst iiow. Fresh feed isintroduced to the systemat the lowest reactor by pipe 5 and hydrocarbonsare withdrawn from the top of that reactor and passed by the second pipe5 to the next higher reactor. .Additional charge may, and preferably isintroduced at this point through pipe I2 and 3 mixed with the materialwithdrawn from the iirst reactor, as by orice mixers II in the line 5. Asimilar arrangement. is found between each pair of adjacent reactors inthe series. At the highest reactor hydrocarbon is withdrawn by pipe I3and passed to a settling zone I4 wherein catalyst entrained in thehydrocarbon is permitted to settle out and is returned to the samereactor by pipe I5. Product' is withdrawn from the separator I4 by lineI6.

In a typical use of the apparatus shown, isobutane is alkylatedwithbutenes in the presence of hydrogen iluoride. The catalyst iscontinuously introduced at 'I and withdrawn at 9 while stronglyselective alkylation is practiced by varying the paraffin to olen ratioat different charge lines. The catalyst in each of the reactors ismaintained at 50 to 60 F. and the charge to each reactor is preheated toabout 175 F. at each stage.

. The charge to the first reactor has a molar ratio of 20 to 1 (paramnto oleiin). Between the first and second reactors, an equal quantity ofcharge having a molar ratio of 10 to 1 is added while the charge to thethird reactor included product and unreacted hydrocarbons from the iirsttwo reactors plus a third charge equal in quantity to the ilrst buthaving a molar ratio of 5 to -1. A

In a typical operation according try-,the invention, a mixture ofisobutane andbutenes containing 8% olen was preheated to '21;0F, andcharged at 220 pounds per square inch through'an' atomizing device intothe bottom of a body of hydrogen fluoride at 100 F. and 120 poundspressure. The hydrocarbons were withdrawn from above the acid, mixedwith 9.3% by-weight of butenes and charged to hydrogen fluoride underthe conditions recited above. produced had an octane number of 89.8 anda uorine contentof 0.0043%.

By comparison, a -run made in a single reactor under identical`,conditions but charging an amount of oleiin equivalent tothat added inboth the above stages produced an alkylate having an octane number of88.6 and a fluorine content of 0.0081%.

The distillation data tabulated below shows further advantages inherentin the multiple stage The alkylate so :Madama 4 We claim: Y A processfor alkylation reaction between isoparamns and oleflns'whichvcomprisescontinuously injecting a vapor phase mixture of isoparafilns and oleiinsas bubbles into a body of liquid hydrogen uoride in the first of aseries of successively higher aikylation zones each containing' a bodyof liquid hydrogen uoride, continuously transferring hydrocarbons fromabove the said body of liquid hydrogen fluoride in each oi said zonesexcept the uppermost to the zone next thereabove by vaporizing said`hydrocarbons and injecting the vapors so produced into the body ofliquid hydrogen fluoride in said next zone, adding most of said zonesand continuously removing from the series liquid hydrocarbonreaction'mixture resulting from injection of Vapor phase hydrocarbonsinto said bodies of liquid hydrogen REFERENCES CITED The followingreferences `'are of record in the iile of this patent:

UNITED STATES PATENTS Number .Name Date 1,625,195 DickeyQ Api". 19, 19272,009,347 vSheldon July 23, 1935 v2,091,645 McConnell Aug. 31, 19372,173,452 'Merley Sept, 19, 1939 2,380,010 Arnold July 10, 1945'2,374,262 Anderson Apr. 24, 1945 2,260,990 Goldsby et al Oct. 28, 1941FOREIGN PATENTS Number Country Date 32,355 Austria Mar- 26, 1908

